Hello, I have a 2013 Jaguar XF. It has been two years since I owned the car. Recently, my car has been blacking out randomly. Sometimes in the middle of the day or sometimes at night and in the morning. So this is what is happening right now:
I try to start my car with my foot on the brake pedal and push start. All the lights will work normally for about 2 seconds, and before the engine starts, the car will go all black, meaning no power at all. After that, I couldn't even lock or unlock my car; there was no power. The first time this happened, I thought it was the battery, so I went to the auto store and got it checked, and the result was that the main battery was bad. so I replaced it. the Aux Battery, starter, and alternator came out good. it happened again. I went to the store to check my battery, and now the Aux Battery, starter, and alternator came out bad. now I don't know what to do. I don't want to keep replacing parts and having the same problem. Does anyone have any suggestions or deal with a similar situation?

 

I suggest you check all the connections on the cable from the battery to the starter, also the earth connections. This can happen with a loose or dirty connection.
The other thing that comes to mind is, are you leaving the car unlocked? I live in a fairly isolated country location and don't usually bother locking my cars, but with this car there are a number of systems that stay active and drain the battery unless the car is locked.

 

Loose battery connections for me!

 

thank you for the suggestions
I will check all the connections tomorrow and I lock my car every time I leave.
I will try to record the next time that happens so that you guys have a better idea of what is happening.

 

the other thing is that when I turn on the without pressing the brake, everything turns on normally, but when I try to start it dies.

 

Just turning stuff on is a relatively low load compared to the starter motor. The high amp draw of the starter will break the poor connection. So it still fits that possible diagnosis.